t_errno

- XTI error return value

Synopsis

#include <xti.h>

Description

This error return value is part of the XTI interfaces that evolved
from the TLI interfaces. XTI represents the future evolution of these interfaces.
However, TLI interfaces are supported for compatibility. When using a TLI interface that
has the same name as an XTI interfaces, a different headerfile, <tiuser.h>,
must be used. Refer the the TLI COMPATIBILITY section for a description of
differences between the two interfaces.

t_errno is used by XTI functions to return error values.

XTI functions provide an error number in t_errno which has type
int and is defined in <xti.h>. The value of
t_errno will be defined only after a call to a XTI function
for which it is explicitly stated to be set and until it
is changed by the next XTI function call. The value of
t_errno should only be examined when it is indicated to be valid by
a function's return value. Programs should obtain the definition of t_errno
by the inclusion of <xti.h>. The practice of defining t_errno in
program as externintt_errno is obsolescent. No XTI function sets
t_errno to 0 to indicate an error.

It is unspecified whether t_errno is a macro or an identifier with
external linkage. It represents a modifiable lvalue of type int. If
a macro definition is suppressed in order to access an actual object
or a program defines an identifier with name t_errno, the behavior
is undefined.

The symbolic values stored in t_errno by an XTI function are
defined in the ERRORS sections in all relevant XTI function definition pages.

TLI COMPATIBILITY

t_errno is also used by TLI functions to return error values.

The XTI and TLI interface definitions have common names but use different
header files. This, and other semantic differences between the two interfaces are described
in the subsections below.

Interface Header

The XTI interfaces use the header file, <xti.h>. TLI interfaces should not use
this header. They should use the header:

#include <tiuser.h>

Error Description Values

The t_errno values that can be set by the XTI interface but
cannot be set by the TLI interface are: